Sony has been recently showing an unprecedented acceptance of the PC platform in recent months, largely thanks to recent successes. Fans undoubtedly had been asking for PC ports in some capacity, but PlayStation in particular has always been a stickler with platform exclusivity in most scenarios. However, when Guerilla Games and Sony decided to port Horizon: Zero Dawn to PC, the game was met with sales success on par with that of The Witcher 3 on release. Evidently the game was successful enough that PlayStation is doubling down on its PC support by releasing Sony Bend's Days Gone, potentially followed by more exclusives coming down the line in 2021.
While games like Days Gone and the already-released Horizon: Zero Dawn are understandable additions, not all exclusives may be created equal. First-party exclusives like the aforementioned titles will be far easier to add to PC with Sony's new expansion initiative compared to others. Examples like Bloodborne, Persona 5, Final Fantasy 7 Remake, and others, these third-party developers are entirely dependent on each game's respective publisher for a PC port. Sony carries no weight in influencing the decision to port those games to PC, regardless of whether developers/publishers like Square Enix or Sega/Atlus have shown support for the platform in the past.
Bringing PS4-Defining Experiences to PC
As for titles like Days Gone or Horizon Zero Dawn, it makes sense that each game would be ported to PC. Sony CEO Jim Ryan had stated that many of the PS4's exclusives have an opportunity to expose/expand to a wider audience. The PC platform in particular has played host to plenty of examples of renewed success on re-released games, regardless of how old or new they may be. Horizon Zero Dawn in particular is the prime example of this, as the game saw huge adoption post-release on Steam. With an estimated number of sales above one million, and peak concurrent players rounding out above 56,000 at release, Horizon Zero Dawn on PC was a significant success.
Presumably, Days Gone is looking to repeat Horizon Zero Dawn's success, especially after its release on PS4. The game wasn't necessarily the critical success that Horizon Zero Dawn became, but Days Gone certainly saw similar commercial success. Plus, many of the release issues that Days Gone had initially was eventually updated/patched out, and the game now performs very well. PC being the definitive graphical benchmark for success, adding Days Gone to the Windows platform will only do well for the game. However, Jim Ryan's words regarding wider acceptance of the PC platform applies to these titles, moreso than any of the third-party games on PS4.
Sony's Comments Don't Apply to All Exclusives
Third-party exclusive games are a different story, but that doesn't necessarily mean they won't be ported to the PC platform at all. What it does mean is that Sony's comments on PlayStation's PC adoption don't necessarily carry weight for any titles from publishers like Square Enix. Now, to be fair, Square Enix has been welcoming the PC platform moreso than ever in recent years. Final Fantasy 15's 2018 port to PC kicked off a series of various ports ranging from Chrono Trigger to Final Fantasy 8 Remastered. Sega and Atlus are kicking off a similar trend with the Persona series, starting with Persona 4 Golden, and most recently with Persona 5 Strikers.
However, with examples like FromSoftware's Bloodborne, or Bluepoint Games' Shadow of the Colossus or Demon's Souls, it's not necessarily the same story. Those games have yet to see a PC release, though the exact reason why is undiscernible currently. The key thing about these publishers is that they've worked on both third-party exclusives and multiplatform releases. Neither is specifically owned or acquired by Sony Interactive Entertainment, so the onus is on each publisher/developer to decide whether it supports the Windows platform or not. Many fans still find it weird that Bloodborne still hasn't come to PC, when other FromSoftware games have.
The Onus of PC Ports Is On Third-Party Developers/Publishers
Does that definitively mean games like Bloodborne or Persona 5 can't come to Windows? No, absolutely not. However, it does mean that those developers and publishers are free to determine a time frame (if at all) when those games are optimized and/or ported to PC. The aforementioned example of Square Enix are also a prime example of both sides. Recently, PC ports of Square Enix games (Octopath Traveler, Kingdom Hearts) have been a lot quicker on the draw than previous efforts. However, games like Final Fantasy 7 Remake do have confirmed PC versions, but have yet to see a release on the platform.
Third-party developers and publishers are largely left to each's own devices when it comes to supporting the PC platform, so Jim Ryan's words don't apply to them specifically. While some publishers have been more than willing to support the Windows platform for game releases, others have been a bit less supportive of the platform in key areas. Considering how nebulous PlayStation's console exclusivity restrictions are, they typically don't extend much longer than a year for third-party games. It's really up to the developers/publishers, which means they aren't necessarily attributed to Sony's renewed support of the Windows platform.